Two non-parallel straight lines have an intersection somewhere: With some simple math from highschool you know that f1(x) = 3 + x and f2(x) = 5 - x intersect at (1, 4). If you want to draw f1 you will start with placing dots at (0, 3) and (-3, 0) and then draw a a line through it, and the same for f2 at (5, 0) and (0, 5). The lines then will cross at (1, 4).
The container can be found at:
(S 34° 11.891, E 150° 58.246) - (S 34° 11.845, E 150° 58.680)
(S 34° 11.795, E 150° 58.446) - (S 34° 11.968, E 150° 58.387)